Doorcheck



Aug. 12 1924.

A. SCHNITZLER DOORCHECK 1 L e e h s S l e e h S 2 2 2 9 Am h C r a M d el 1 F lnveizifor Aug. 12 1924.

A. SCHNITZLER DOORCHECK Filed March '4, ,1922

2 Sheets-Shem 2 Patented Aug. 12, 1924.

UNITED STATES PATENT oFFm DO ORCHECK.

Application filed. March 4, 1922. Serial No. 541,204.

To all whom it may concern Be it known that I, ABRAHAM 'SCIINITZLER, acitizen of the United States, and resident of Roxbury, in the county ofSuffolk and State of Massachusetts, have invented an Improvement inDoorchecks, of which the following description, in connection with theaccompanying drawings, isa specification, like letters on the. drawingsrepresenting like parts.

My present invention is directed to spring actuated door closers orchecks, and the object of the invention is to improve and perfect suchapparatus and furthermore to provide means which will positively insurethe closing of the door, as well as to prevent such closing by suddenslamming, jerking, or amm1ng-.

In prior spring door closers or door checks a great difficulty'has beenexperienced in providing an apparatus which will act efliciently andpowerfully to close the door, particularly if the door is only partlyopened and yet which will not produce a violent slammingi or jarring inthe closing. In order to insure the positive closing of the door, allprior devices of which I am aware have required the use of a strong andpowerful spring, since its action is relatively slight at the extremedoor closing movement. In other words, the final movement of the doorclosing action was always at theweakest part of the doom closing means."

Therefore an oversize spring or power was requisite to effect this finalaction, and such constructions were objectionable when the door wasallowed a full swing because the door check then gained such headway andmomentum as to result in slamming, jarring and a noisy action.

By my invention I have eliminated these prior difficulties, and havedevised novel means and mechanism for producing a strong, powerful andpositive door closing action, which will be at its greatest efiiciencyjust at the final movement for full shutting and positively closing andlatching the door, while also providing means and mechanism which willregulate the force of the spring and prevent undue slamming, jarring ornoises.

With these and other objects in view I have devised my present apparatusherein illustrated in two modified forms. In order to secure a controlof the door closing acas powerful a spring as desired, and preventslamming, even when'the door has its full limit toswing from wide opento shut, and also I secure great power at the last or final few degreesof swing of the door, thus insuring a powerful but quiet closing actionand actual latching of the door.

Further details of the invention, advantages and novel combinations ofparts will be hereinafter more fully pointed out and claimed.

Referring to the drawings, illustrating a preferred embodiment of theinvention,

Fig. l is a diagrammatic plan view of my apparatus as applied to a doorand door jamb;

Fig. 2 is a side View;

Fig. 3 is a longitudional cross-sectional View; and Fig. 4 is afragmentary view of the cam control;

Fig. 5 is ,a modification showing same in plan view;

Fig. 6 being a side view of the modified form shown in Fig. 5; and

Fig. 7 is a vertical plan view.

Fig. 8 is a detail, in section, through an i oil shock cylinder.

Referring to theinvention as illustrated in Figs. 1, 2 and 3 and 4:,myapparatus is adapted to be applied to the door jamb or other fixed part1, and to the swinging door 2. While intended primarily for use as adoor check, it will of course be appreciated that similar uses could bemade of the inven tion, particularly wherein a similar action isdesired. Applied or attached to the fixed part 1- adjacent the door is aplate 8 secured by screws 4 or the like and carrying a lug 5, to whichis pivoted at 6 a forked member 7 having at right angles thereto pivotedconnection with" a sleeve '8. This is, in

effect, a universal joint construction to prevent binding during theoperation of my imtherein a cooperating arm 9, which in turn is pivotedat 1Q: to a rotatable member 12 mounted on a bolt 14 threaded into theouter end 15 of the operating arm connecting my spring and checkingdevice attached to the movable member2 with the attachment forconnection with the fixed member 1.

. The part of 'my apparatus attached to the movable member 2 consistsina cylinder 20 having threaded thereon ends 21. and 22, each end beingpreferably formed with a pair ofears 23 through which bolts or screws 24are'fitted to hold the cylinder to the door 2. The topmost end 21 isformed with a central hub 25, bored to receive a stem or shaft, 30,extending therethrough and carrying on its inner end'a piston 31. Athreaded bolt 32 holds the piston '31 position and the outer surfaces ofthispiston are grooved to carry a t packing 33, which formsasu'bstantially airhas tight sliding joint for the pistonwithin thecylinder 20. The lowermost cap or end 22 is also formedfwith a centralhub 35, recessed torreceive an air+adjusting screw 36. This screw 36 ishollowand has an outlet or opening through the interior hollow portion,po-

siftione d substantially as indicated at 37, to

permit a greater or less current of air therethroughand thereby controlthe speed of movement of the piston 31 on the interior. A ring 38 isfittedwithin the bottom cap 22 on which the piston may rest when inlowermost position, and between the same and the central hub 35, Iprovide a filling of oil 40. This serves'to keep the interior of thecylinder lubricated at all times. 7 V 4 A coiled spring 41 bears betweenthe topmost cap 21 .andthe piston 31 exerting an eX- pan'sibl'e tension,and resisting the upward movement of the piston 31. The apparatus is soarranged that theopening of the door will lift the stem.30 and piston 31against the tension of thespring 41 and at the same time 7 partiallyrotate the stem and piston. Thereupon, on release of the door the spring41 expands and produces a closing action, the air outlet 37 regulatingits movement to a certain extent. j

Surrounding, the stem 30 as. it projects above the cylinder, is a camcarrying sleeve v V 44 wherein a cam path 45 is cut. The rod 15 V isthreaded into thestem 30 and carries also a roll 50 adapted tofit withinthe cam path 45 and be freely rotatablepon the rod 15, a a pin 48holding said roll in its position; I also prefer to fitia bushing 51around the stem 30, as clearly shown in Fig. 3, and a pair of lock nuts52 clamp the bushing and rod together, and said bushing 51 afiiords arigid bearing against which the lock nuts 52 may be threaded to affordadjustment for the tension of the spring 41. This cam path 45 is soformed as to regulate or control the action of the spring, checking sameuntil just before the final limit of movement, when the cam path 50 issuddenly released, as shown at 55, Fig. 4, thus permitting a quick,strong and the full power of the spring 41 to be exerted in its doorclosing action.

The operation of my apparatus will be readily understood. The same beingassembled, the adjusting nut 36 manipulated to permit a quick or slowexit or egress of air to effect the speed of reciprocation of the piston31 and the lock nuts 52 adjusted to limit the tension of the spring 41,the door is swung open and this swinging action produces a relativemovement between the cam member 44, making the roll 50 mount the campath and thereby raising the stem 30 against the tension of the spring41, drawing the piston upwardly and causing the air to rush inunderneath the same. Upon the release of the door the expansible actionof the spring 41 will serve to move the stem 30 downwardly, the stemturning partially and the roll 50 following the cam path untilapproaching the release portion 55, at which point the regulatingtension of the spring 41 is released and at this point also the door hasnearly reached its completely closing action. Thereupon the cam path nolonger restraining the action of the spring 41 and the piston havingnearly traversed the length of the cylinder 20 the roll 50 released andthe full power of the spring is allowed to exert itself on the finalclosing action. The universal joints at the several bearings 6 and 14prevent binding and permit this rotation of the stem 30 and therebyproduces a smooth, uniform powerful and at the end an eificient closingaction.

A modified form of my invention is illustrated in Figs. 5, 6 and 7,wherein the same advantageous features of having a cam controlled actionon the power of the spring regulating its door closing movement whilereleasing this restraining action and permitting the full power of thespring to eflect the final shutting, latching, and firm pushing of thedoor completely shut.

In this form the link extends to the fixed part of the door or j amb-notshown being pivoted at 61 to the arm 62, which latter is pivotallysecured at 63 to a plate 65, which plate has a pair of dependingportions 66 for attachment to the door or movable member. This plate hasformed thereon a raised cam 70 of varying contour, which may be formedas a flange struck up from the plate 65 and extending from the positionindicated at 71 to 72, leaving an opening from the end 72 which isrounded slightly, as clearly shown in Fig. 5, to a second upstandingflange 78. An arm 75 is pivoted at 78 to the lever 62 and a coiledspring 80 has one end pivotally secured at 81 to the lever 62 and itsopposite end also pivotally secured at 82 to the lever 75, being coiledto exert an expansible action between these two pivot points 81 and 82.On the end of the lever 7 5 opposite to the pivot 7 8 is fitted a roll85 in depending position and adapted to traverse the cam 7 O. This rollis of slightly larger diameter than the space between the curved end 72of the cam 70 and the adjacent flange or stop 73.

Upon opening movement of the door to which the plate 65 is attached, theaction of the link and lever 62 serves to compress the spring 80 byswingin the lever 75 to the left, viewing Fig. 5, forcing the roll 85 toride upon and traverse the inner face of the cam 70. Upon release of thedoor the spring 80 acts in its expansible position to move the lever 62and 65 toward the position illustrated in Fig. 5, but the action of thecam path retards this movement, said cam path being so formed as to havean increasing retarding tension during the continued action of thespring, thereby preventing the door from gaining momentum, but movingthe same in a substantially uniform and even manner. However, as thedoor reaches its position about to close, and with the inherent strengthof the spring reduced to normal, and in order to exert increased powerat this critical point in the door closing action, the cam 70 is formedshort of the final closing movement, with the end face 72 rounded off asshown in Fig. 5, so that the retarding action of the cam 70 is relieved,just before the final movement of the spring will close the doorcompletely, thereby affording greater power, i. e., the full power ofthe spring to effect the final few degrees of swinging movement as theroll snaps into the recess afiorded by the end 72 and stop or flange 73.This construction also practically affords a holding lock or toggle tokeep the door shut without latching or looking, considerable force beingrequired to initiate the opening movement which requires the raising ofthe roll 85 against the beveled face 72 of the cam 70 and thereafter arelatively easy movement will complete the opening swing of the door.

In both forms of my invention 1 have secured the important advantagesincident to a retarding cam, thus regulating the closing action andpreventing undue momentum and slamming, while also securing an increasedpower of the spring just at the closing action. I believe these featuresto be distinctly novel in this art and I wish to claim same broadly.

I may substitute for the air cylinder 20 shown in Fig. 3, the oil orother fluid cylinder 88 shown in Fig. 8. This cylinder 88 is closed atthe bottom by a screw cap 89 in which is located a plug screw 90, which,when removed, exposes a hole through which oil or other fluid may beinserted into the cylinder 88. In this cylinder 88 is a piston 91 inwhich is arranged a ball valve 92 controlling a passage 93 and throughwhich the liquid, may flow to one side or the other of the piston.Secured to or formed integral with the piston 91 is a piston rod 94 thatextends upward and has attached thereto the rod 15, in the manner shownin Fig. 3. A passage 95 extends longitudinally through the piston rod 9eand this passage has connected therewith a passage 96 leading to thecylinder 88 at a point above the piston 91. At the intersection of thepassages 95 and 96 is formed a valve seat with which cooperates a valvestem 97 having an operating head (not shown) and by means of which thevalve seat may be covered or uncovered to prevent or allow fluid to flowfrom the lower to the upper side of the piston 91. The operation of thismodification is as follows: the valve stem 97 is adjusted relative tothe valve seat to permit proper flow of the liquid, such as oil, throughthe passages 95 and 96, and the ball valve 92 is operated automaticallyto control the passage 93, which passage is of proper size to allow, inconjunction with the passage 95 and 96, a quick flow of oil or otherliquid from the top to the bottom side of the piston 91.

My invention is further defined and described in the form of claims asfollows:

1. Door closing apparatus of the kind described, comprising a movablelink and lever, a spring permitting opening of the door against itstension and thereafter automatically acting to close said door,restraining means comprising a cam path and roll traversing the same,during its door closing action, so constructed and arranged as torelieve the restraining means just before the closing action iscompleted.

2. Door closing apparatus of the kind described, comprising a movablelink and lever, a spring permitting opening of the door against itstension and thereafter automatically acting to close said door,restraining means comprising a cam path and roll traversing the same,during its door closing action, said cam terminating short of thecomplete door closing action.

Door closing apparatus consisting in spring actuated means to efiect theclosing of the door having mechanism permitting increased power of thespring at the comple- I 7 tion of the door closing movement, a cylinderenclosing said spring'and oil retaining means in the face of saidcylinder.

4. D00r closing apparatus consisting in spring actuated means to effectthe closing of the door having mechanism permitting I increased power ofthe spring at the comtpleticn of the door closing movement, a

cylinder enclosing said spring and oil retaining means in the face ofsaid cylinder, in combination with adjustable means to re 11- late theflow of fluid through said cylin er.

In testimony whereof, I have signed my name to this specification.

ABRAHAM SCHNITZLER.

